1. Field of the Invention
The present invention relates to a photosensitive material processor for processing a photosensitive material by immersing the photosensitive material in a processing solution in a processing tank. In particular the invention relates to a photosensitive material processor causing a replenisher to overflow stably and sequentially in continuous processing chambers for processing, being able to maintain stable performance and process the photosensitive material rapidly.
2. Description of the Related Art
A photosensitive material, for example, a color paper, is processed through processes such as color development, bleach-fixing, washing and the like after exposure.
A color developer is used for color development, a bleach-fixing solution is used for bleach-fixing and tap water or ion exchanged water is used for washing.
These processes are usually performed by a photosensitive material processor such as an automatic developer.
An automatic developer is ordinarily provided with a color development tank, a bleach-fixing tank, and a plurality (about four) of washing tanks, and a so-called cross-over type developer is common. When conveying a photosensitive material from a processing tank to the next processing tank, the automatic developer takes out the photosensitive material once from the processing tank and conveys the photosensitive material through the air to the next tank.
In recent years, there has been a desire by the marketplace for quick processing of photosensitive material, and a photosensitive material processor of a type that sequentially transports the photosensitive material through a plurality of processing tanks without conveying the photosensitive material through the air has been proposed.
An example of the type of photosensitive material processor that sequentially transports the photosensitive material through a plurality of processing tanks in Japanese Patent Laid-Open (JP-A) No. 9-015812. In FIG. 4 of this publication, a type of a photosensitive material processor including a plurality of washing tanks arranged vertically and horizontally which allows the photosensitive material to pass through the plurality of washing tanks in sequentially, is shown.
On each partition wall of adjacent tanks in the conveyance direction of the photosensitive material, a slit-shaped passage equipped with a blade made from an elastic material is provided. The photosensitive material is conveyed to the washing tank that is downstream by deforming the blade elastically. The slit-shaped passage is arranged to be closed by the blade after the photosensitive material has passed.
However, in the photosensitive material processor disclosed in JP-A No. 9-015812, there is no opening that contacts the air or free water surface. Thus, a so-called cascade, in which the washing water flows in a counterflow, which is opposite to the flow of the photosensitive material processing, by an overflow, cannot be performed as it can in existing washing tanks. Consequently, it is necessary to arrange a plurality of water pumps to pump washing water to each washing tank sequentially. This complicates construction of the photosensitive material processor and increases the cost thereof.
Another photosensitive material processor, which is able to reduce the number of pumps by disposing a bypass between processing tanks, is disclosed in U.S. Pat. No. 6,071,020.
However, a washing solution in a first chamber of the washing tank, which is upstream relative to the processing direction, is the dirtiest and has the highest specific gravity because of adherent solutions (such as a fixing solution) being brought into the first chamber by the photosensitive material to be processed.
As a result, in the bypass in which solution always continues as disclosed in U.S. Pat. No. 6,071,020, a purpose thereof is achieved when the photosensitive material is processed continuously. However it has been found that an unfavorable back flow occurs from the difference in the specific gravity of the washing solutions when processing of the photosensitive material stops.
The present invention has been made to solve the foregoing problems, and an object of the invention is to provide a photosensitive material processor having a simple construction and capable of quick processing without back flow of the processing solution occurring.
A first aspect of the invention is a device for processing a photosensitive material using processing solution, the device comprising: a plurality of processing chambers for storing processing solution therein, at least one of the processing chambers being lower than another processing chamber, paths connecting each processing chamber to another, a blade disposed at the path for permitting the photosensitive material to pass along the path by deforming resiliently and for inhibiting passage along the path of the processing solution in the processing chamber when the photosensitive material is not passing, a conveyance mechanism for conveying the photosensitive material through the processing chambers, a replenishment device for replenishing the processing solution, in accordance with a processed quantity of the photosensitive material, to at least one processing chamber that is downstream of another chamber relative to conveyance direction of the photosensitive material, a bypass for placing each processing chamber that is downstream of another processing chamber relative to conveyance direction of the photosensitive material in fluid communication with the another processing chamber for passage of the processing solution therethough, and a check valve disposed at each bypass for allowing the processing solution which flows from the processing chamber that is downstream relative to conveyance direction of the photosensitive material to the another processing chamber, and for preventing the processing solution from flowing from the another processing chamber to the downstream processing chamber, the check valve comprising a valve seat and a valve body, the valve body has a specific gravity different from a specific gravity of the processing solution and is urged against the valve seat by a force generated by the difference of specific gravity between the valve body and the processing solution.
In above arrangement of the photosensitive material processor, the photosensitive material is conveyed sequentially through the in a plurality of processing chambers by the conveying device and processed by the processing solution of each processing chamber while being conveyed.
When the photosensitive material is conveyed to the next processing chamber, a leading edge portion of the photosensitive material deforms elastically the blade by abutting on the blade. Thus, the photosensitive material can enter into the next processing chamber through the narrow path.
The photosensitive material contacts the blade and slides while being conveyed, which prevents the processing solution on the upstream side adhered on the photosensitive material from entering into the processing chamber on the downstream side.
Furthermore, the blade inhibits passage of the processing solution when the photosensitive material is not being conveyed.
A replenishment device replenishes the processing solution in the processing chamber that is downstream relative to conveyance direction of the photosensitive material according to processing quantity of the photosensitive material (namely, deterioration of the processing solution).
By replenishing of the processing solution in the processing chamber that is downstream relative to conveyance direction of the photosensitive material, the processing solution is replenished via bypass in the processing chamber that is upstream relative to conveyance direction of the photosensitive material.
The valve body is urged against the valve seat with the force generated by the difference in specific gravity between the processing solutions. However, the flow of the processing solution from the replenishment is not prevented because the valve body is separated from the valve seat with pressure generated by forcedly replenishing of the processing solution.
On the other hand, when the processing solution is not being supplied, the valve body is urged against the valve seat with the force generated by the difference in the specific gravity between the processing solution and the valve body. Thus, the bypass closes to prevent the back flow of the processing solution.
The specific gravity of the processing solution in the upper processing chamber that is upstream relative to conveyance direction of the photosensitive material may become larger, because of another processing solution being brought into this processing chamber adhering to the photosensitive material, than the specific gravity of the processing solution in the lower processing chamber that is downstream relative to conveyance direction of the photosensitive material. However, even in this case, because there is the difference in the specific gravity between the valve body and the processing solution, the valve body is urged against to the valve seat with the force generated by the difference in the specific gravity to close the bypass.
Consequently, the processing solution having larger specific gravity that is upstream relative to conveyance direction of the photosensitive material, namely, the waste processing solution, never flows into the processing chamber that is downstream relative to conveyance direction of the photosensitive material.
In the first aspect, when replenishing the processing solution, A is specific gravity of the valve body disposed at the bypass through which the processing solution flows upward and B is specific gravity of the processing solution stored in the processing chamber that is upstream of the bypass relative to conveyance direction of the photosensitive material, whereas A/B is set to be at least 1 and less than 1.5.
In above described arrangement of the photosensitive material processor, the processing solution stored in the processing chamber that is upstream relative to conveyance direction of the photosensitive material tends to flow downward in the bypass in which the processing solution can flow upward when supplying the processing solution. Consequently, the specific gravity of the valve body is set to be larger than that of the processing solution. When the processing solution is not supplied, the valve body sinks in the processing solution so that a force (opposite to a buoyancy force) can be generated by the sinking, by which force the valve body closes the bypass.
The reason why A/B is at least 1 and less than 1.5 is that, when A/B is not lower than 1.5, the force closing the bypass becomes larger but the valve body does not move unless a large difference in pressure is given when replenishing the processing solution, which prevents the processing solution from being replenished to the processing chamber that is upstream relative to conveyance direction of the photosensitive material.
Further, in the first aspect, when replenishing the processing solution, A is specific gravity of the valve body disposed at the bypass through which the processing solution flows downward and B is specific gravity of the processing solution stored in the processing chamber that is upstream of the bypass relative to conveyance direction of the photosensitive material, whereas A/B is set to be at least 0.8 and less than 1.
In above described arrangement of the photosensitive material processor, the specific gravity of the valve body is set to be smaller than that of the processing solution. When the processing solution is not supplied, the valve body floats in the processing solution so that a force (buoyancy) can be generated by floating, which force causes the valve body to close the bypass.
The reason why A/B is at least 0.8 is that, when A/B is less than 0.8, the force closing the bypass becomes larger but the valve body does not move unless a large difference in pressure is given when replenishing the processing solution, which prevents the processing solution from being replenished to the processing chamber that is upstream relative to conveyance direction of the photosensitive material.
Furthermore, in the first aspect, the valve body includes a rotatable mechanism rotated by the processing solution flowing near the valve body.
When the specific gravity of the processing solution in the processing chamber that is above becomes larger than that of the processing solution in the processing chamber that is below, the processing solution in the upper processing chamber begins to flow to the lower processing chamber via the bypass, the valve body must stop the flow of the processing solution. However, because the force generated by the difference in the specific gravity and moves the valve body is small, it is possible that the valve body will become caught in the bypass and not move.
However, in the above described arrangement of the photosensitive material processor, because the valve body is rotated with a rotating force generated by the flow of the processing solution near the valve body there is no risk of the valve body becoming caught in the bypass and not closing the bypass.
Moreover, in the first aspect, the bypass is a through hole formed in a partition separating the processing chamber that is downstream relative to conveyance direction of the photosensitive material from the processing chamber that is upstream relative to conveyance direction of the photosensitive material.
It is not necessary to install a pipe or the like outside of the processing chambers because the bypass is the through hole in the partition separating the processing chamber that is downstream relative to conveyance direction of the photosensitive material from the processing chamber that is upstream relative to conveyance direction of the photosensitive material. As a result, the number of parts of the photosensitive material processor does not increase and the cost can be held down.
A second aspect of the invention, is a device for processing a photosensitive material using processing solution, the device comprising: a plurality of processing chambers for storing processing solution therein, at least one of the processing chambers being lower than another processing chamber, paths connecting each processing chamber to another, a blade disposed at the path for permitting the photosensitive material to pass along the path by deforming resiliently and for inhibiting passage along the path of the processing solution in the processing chamber when the photosensitive material is not passing, a conveyance mechanism for conveying the photosensitive material through the processing chambers, a replenishment device for replenishing the processing solution, in accordance with a processed quantity of the photosensitive material, to at least one processing chamber that is downstream of another chamber relative to conveyance direction of the photosensitive material, a bypass for placing each processing chamber that is downstream of another processing chamber relative to conveyance direction of the photosensitive material in fluid communication with the another processing chamber to pass the processing solution therethough, and a check valve disposed at each bypass for allowing the processing solution to flow from the processing chamber that is downstream relative to conveyance direction of the photosensitive material to the another processing chamber, and for preventing the processing solution from flowing from the another processing chamber to the downstream processing chamber, wherein the plurality of processing chambers is disposed such that the photosensitive material is conveyed downwards through at least one of the processing chambers that is lower after being conveyed through the another processing chamber and then is conveyed upward through at least one other processing chamber higher than the lower chamber, the check valve disposed between the processing chambers, through which the photosensitive material is conveyed from the higher to the lower processing chamber, comprises a valve seat and a valve body, the valve seat being disposed under the valve body, the valve body having a specific gravity greater than a specific gravity of the processing solution and being urged against the valve seat by a force generated by the difference in specific gravity between the valve body and the processing solution; and the check valve being disposed between the processing chambers through which the photosensitive material is conveyed from the lower to the higher processing chamber, comprises a valve seat and a valve body, the valve seat being disposed above the valve body, the valve body having a specific gravity less than a specific gravity of the processing solution and being urged against the valve seat by a force generated by the difference in specific gravity between the valve body and the processing solution.
In above arrangement of the photosensitive material processor, the photosensitive material is conveyed sequentially through the plurality of processing chambers by the conveying device and processed by the processing solution of each processing chamber while being conveyed.
When the photosensitive material is conveyed to the next processing chamber, a leading edge portion of the photosensitive material deforms elastically the blade by abutting on the blade. Thus, the photosensitive material can enter into the next processing chamber through the narrow path.
The photosensitive material contacts the blade and slides while being conveyed, which prevents the processing solution on the upstream side adhered on the photosensitive material from entering into the processing chamber on the downstream side.
Furthermore, the blade inhibits passage of the processing solution when the photosensitive material is not being conveyed.
In a normal case, namely, when the processing solution is not being supplied, in the check valve provided between the processing chambers through which the photosensitive material is conveyed from the above to the below, the valve body is urged against to the valve seat there below with the force generated by the difference in specific gravity between the valve body and the processing solution to close the bypass because the specific gravity of the valve body is larger than that of the processing solution.
On the other hand, in the check valve provided between the processing chambers which the photosensitive material is conveyed from below to above, the valve body is urged against to the valve seat thereabove with the force generated by the difference in specific gravity between the valve body and the processing solution to close the bypass because the specific gravity of the valve body is smaller than that of the processing solution.
As the processing progresses, the specific gravity of the processing solution in the upper processing chamber that is upstream in the conveyance direction of the photosensitive material may become larger than the specific gravity of the processing solution in the lower processing chamber that is downstream in the conveyance direction of the photosensitive material because of another processing solution being brought into this upstream processing chamber by adhering to the photosensitive material. However, even in this case, because there is the difference in the specific gravity between the valve body and the processing solution, the valve body is urged against the valve seat with the force generated by the difference in the specific gravity, keeping the bypass closed.
Consequently, even in the case in which the processing chamber, which contains the processing solution that is dirty and has larger specific gravity, is disposed above the processing chamber, which is upstream relative to conveyance direction of the photosensitive material and contains the processing solution that is less dirty and has smaller specific gravity, the processing solution, which is dirty and has the larger specific gravity does not flow into the processing chamber disposed on the lower side that is downstream relative to conveyance direction of the photosensitive material.
The supplying device supplies the processing solution to the processing chamber that is downstream relative to conveyance direction of the photosensitive material according to the processed quantity of the photosensitive material (namely, deterioration of the processing solution).
If the processing solution is replenished to the processing chamber that is downstream relative to conveyance direction of the photosensitive material, the valve body is separated from the valve seat with the pressure generated by the replenishment. Thus, the flow of the processing solution by the replenishment is not prevented.
Accordingly, the processing solution is replenished to the processing chamber that is upstream relative to conveyance direction of the photosensitive material through the bypass.